rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=da14/1/0x4000000000000000 softirq=89676/89677 fqs=1 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5142/1:b..l P9627/1:b..l (detected by 0, t=10505 jiffies, g=133689, q=118 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 24583 Comm: syz.4.5903 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:467 [inline] RIP: 0010:lock_is_held_type+0x10d/0x190 kernel/locking/lockdep.c:5720 Code: 95 c0 31 ed 39 c1 40 0f 94 c5 eb 05 bd 01 00 00 00 48 c7 c7 20 29 8c 8a e8 60 12 00 00 b8 ff ff ff ff 65 0f c1 05 13 5e d2 75 <83> f8 01 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 RSP: 0018:ffffc900001e0c88 EFLAGS: 00000057 RAX: 0000000000000001 RBX: ffff888076d5da00 RCX: 74841382b81a1f00 RDX: ffff888076d5da00 RSI: ffffffff8a8c2920 RDI: ffffffff8adf5de0 RBP: 0000000000000001 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff5200003c188 R12: 0000000000000001 R13: 0000000000000046 R14: ffff888058757300 R15: ffff888076d5e508 FS: 00007fd58ee246c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd58ee23ff8 CR3: 000000005e8bf000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:283 [inline] advance_sched+0x6b/0x950 net/sched/sch_taprio.c:707 __run_hrtimer kernel/time/hrtimer.c:1751 [inline] __hrtimer_run_queues+0x522/0xc90 kernel/time/hrtimer.c:1815 hrtimer_interrupt+0x399/0x980 kernel/time/hrtimer.c:1877 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline] RIP: 0010:static_key_false include/linux/jump_label.h:207 [inline] RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:147 [inline] RIP: 0010:wrmsrl arch/x86/include/asm/msr.h:262 [inline] RIP: 0010:native_x2apic_icr_write arch/x86/include/asm/apic.h:239 [inline] RIP: 0010:__x2apic_send_IPI_dest arch/x86/kernel/apic/x2apic_phys.c:126 [inline] RIP: 0010:x2apic_send_IPI+0x70/0xc0 arch/x86/kernel/apic/x2apic_phys.c:48 Code: f0 48 c1 e8 03 42 0f b6 04 20 84 c0 75 37 41 0f b7 16 0f ae f0 0f ae e8 83 fb 02 b8 00 04 00 00 0f 45 c3 b9 30 08 00 00 0f 30 <66> 90 5b 41 5c 41 5e 41 5f c3 48 c7 c7 c0 97 99 8c 4c 89 f6 e8 e7 RSP: 0018:ffffc9000d567778 EFLAGS: 00000206 RAX: 00000000000000fb RBX: 00000000000000fb RCX: 0000000000000830 RDX: 0000000000000000 RSI: 00000000000000fb RDI: 0000000000000000 RBP: ffffc9000d567850 R08: ffff8880b8f3bdd7 R09: 1ffff110171e77ba R10: dffffc0000000000 R11: ffffed10171e77bb R12: dffffc0000000000 R13: 1ffff92001aacef8 R14: ffff8880b8e219b0 R15: ffffffff8c65f980 arch_send_call_function_single_ipi arch/x86/include/asm/smp.h:109 [inline] send_call_function_single_ipi+0x155/0x210 kernel/sched/core.c:3786 smp_call_function_many_cond+0xb0d/0x1250 kernel/smp.c:978 clock_was_set+0x7ee/0x8d0 kernel/time/hrtimer.c:988 timekeeping_inject_offset+0x5cc/0x670 kernel/time/timekeeping.c:1395 do_adjtimex+0x45a/0xa00 kernel/time/timekeeping.c:2444 do_clock_adjtime kernel/time/posix-timers.c:1155 [inline] __do_sys_clock_adjtime kernel/time/posix-timers.c:1167 [inline] __se_sys_clock_adjtime kernel/time/posix-timers.c:1158 [inline] __x64_sys_clock_adjtime+0x240/0x320 kernel/time/posix-timers.c:1158 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fd58df9e019 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd58ee24028 EFLAGS: 00000246 ORIG_RAX: 0000000000000131 RAX: ffffffffffffffda RBX: 00007fd58e226090 RCX: 00007fd58df9e019 RDX: 0000000000000000 RSI: 0000200000000280 RDI: 0000000000000000 RBP: 00007fd58e03500c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd58e226128 R14: 00007fd58e226090 R15: 00007ffec1783498 task:syz-executor state:R running task stack:22928 pid:9627 ppid:9618 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5246 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6563 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6875 irqentry_exit+0x63/0x70 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:lock_acquire+0x225/0x4a0 kernel/locking/lockdep.c:5680 Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f0 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04 RSP: 0018:ffffc900032376a0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 84a344f0993cee00 RDX: 0000000000000000 RSI: ffffffff8a8c2920 RDI: ffffffff8adf5de0 RBP: ffffc900032377c0 R08: dffffc0000000000 R09: 1ffffffff2162048 R10: dffffc0000000000 R11: fffffbfff2162049 R12: 0000000000000001 R13: 1ffff92000646ee0 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock include/linux/rcupdate.h:791 [inline] percpu_ref_put_many include/linux/percpu-refcount.h:330 [inline] percpu_ref_put+0x2e/0x100 include/linux/percpu-refcount.h:351 slab_alloc_node mm/slub.c:3359 [inline] slab_alloc mm/slub.c:3367 [inline] __kmem_cache_alloc_lru mm/slub.c:3374 [inline] kmem_cache_alloc+0x18b/0x2f0 mm/slub.c:3383 vm_area_dup+0x23/0x1a0 kernel/fork.c:468 dup_mmap kernel/fork.c:647 [inline] dup_mm kernel/fork.c:1548 [inline] copy_mm+0xb13/0x1680 kernel/fork.c:1597 copy_process+0x19a6/0x40c0 kernel/fork.c:2358 kernel_clone+0x24b/0x900 kernel/fork.c:2765 __do_sys_clone kernel/fork.c:2906 [inline] __se_sys_clone kernel/fork.c:2890 [inline] __x64_sys_clone+0x1a7/0x220 kernel/fork.c:2890 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7febf51c6a92 RSP: 002b:00007ffd45a99100 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffd45a99100 RCX: 00007febf51c6a92 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffd45a9928c R08: 0000000000000000 R09: 0000000000000001 R10: 000055558125f7d0 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000110fb5 R15: 00007ffd45a992e0 task:kworker/u4:8 state:R running task stack:22096 pid:5142 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5246 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6563 preempt_schedule_notrace+0xd9/0x120 kernel/sched/core.c:6825 preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35 rcu_is_watching+0x76/0xa0 kernel/rcu/tree.c:722 rcu_read_unlock include/linux/rcupdate.h:820 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0x1fe/0x600 net/batman-adv/network-coding.c:719 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: rcu_preempt kthread starved for 10500 jiffies! g133689 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:27616 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5246 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6563 schedule+0xb9/0x180 kernel/sched/core.c:6639 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x303/0x1350 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 6346 Comm: kworker/u4:15 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline] RIP: 0010:smp_call_function_many_cond+0x1148/0x1250 kernel/smp.c:998 Code: 41 8b 1f 89 de 83 e6 01 31 ff e8 73 ff 0a 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 0a e8 ff fb 0a 00 e9 34 ff ff ff f3 90 <41> 0f b6 04 1c 84 c0 75 14 41 f7 07 01 00 00 00 0f 84 17 ff ff ff RSP: 0018:ffffc90005b87800 EFLAGS: 00000293 RAX: ffffffff81773243 RBX: dffffc0000000000 RCX: ffff888026a80000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90005b87960 R08: ffffffff90b10247 R09: 1ffffffff2162048 R10: dffffc0000000000 R11: fffffbfff2162049 R12: 1ffff110171e8219 R13: ffff8880b8e3bdc0 R14: 0000000000000001 R15: ffff8880b8f410c8 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f65dafd9000 CR3: 000000000c88e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1165 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1574 [inline] text_poke_bp_batch+0x2b7/0x850 arch/x86/kernel/alternative.c:1774 text_poke_flush arch/x86/kernel/alternative.c:1965 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1972 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x11f/0x240 kernel/jump_label.c:207 static_key_enable+0x16/0x20 kernel/jump_label.c:220 toggle_allocation_gate+0xba/0x470 mm/kfence/core.c:821 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295